Cerbellum Flashcards
What is the cerebellum responsible for?
Co-ordinating voluntary movements (the timing of the events)
What would be found in the white matter of the cerbellum?
Axons to/from the cortex
Deep cerebellar nuclei
There are 3 functional parts of the cerebellum, name them
Archicerebellum
Paleocerebellum
Neocerebellum
What is the function of the Archicerebellum?
Posture and balance, big input from the vestibular system. Another name for it is the vestibulocerebellum
What does the paleocerbellum do?
Nothing in humans
What does the neocerebellum do?
Coordination of voluntary movements
How does information reach the cerebellar cortex?
Directly via the pons
Indirectly via the inferior olive nucleus.
All input to cerebellum is through nucleus? True or Flase
False, all input is through cortex.
All output is from the nucleus of the cerebellum? True or Flase
True
Connections from the pons to the cerbellum are called?
Mossy fibres
Connections from the inferior olive to the cerebellum are called ?
Climbing fibres
How does the cerebellum receive information about the motor neurone activity?
Through collaterals of the CS tract.
What part of the brain is responsible for muscle memory?
Cerebellum (neo)
What are preferential pathways?
A circuit that is modified by experience
What is the only output of the Cortex?
Purkinje cells, these are key to muscle memory.
Do mossy fibres raise an action potential in the Purkinje cells?
No, a mossy fibre will touch many purkinje cells, and will excite them, but not enough to cause an AP
Which type of cerebral input makes more Purkinje connections?
Mossy fibres, they contact 1000+. Climbing fibres make a 1:1 contact.
Do Climbing fibres evoke an AP in purkinje cells?
Yes.
What effect does an AP in a Purkinje cell have on the cerebellum?
It inhibits the dentate nucleus, which is the method of communication with the MC.
What effect have mossy fibres on the Dentate nucleus?
Stimulate
How does muscle memory happen?
Body uses all available senses to pick a climbing fibre. If the correct response is exhibited, it should be repeated. A purkinje cell undergoes synaptic strenthening, meaning that a mossy fibre can now evoke an AP. climbing fibre no longer needed to perform task, and it becomes automatic.
Is synaptic strengthening permanent?
YES
How is timing determined by muscle memory?
The strong purkinje cells will Discharge in a temporal pattern. As they inhibit the dentate nucleus message to the MC, there will be timed periods on inhibition in the message. This is smooth, reliable and automatic.
What is the name given to a global defecit in coordintion?
Ataxia, often due to cerebellar damage
